The authors couldn't resist a jab at Trump and Pence. ProPublica also couldn't resist another jab at Trump and Pence for what they said about testing about a month ago, including a picture, caption and link to an earlier ProPublica article. As I observed here about a New York Times article, the ProPublica article tried to refute what Trump and Pence said by invoking positivity rates, despite Trump and Pence having said nothing about the positivity rate.
This site shows a graph of positivity rates for the USA. One can also select to see the graph for an individual state.
It seems a test result for an individual is either positive or negative, with no indication of how much positive if positive. (At least I could not find any such indication on the Internet.) If so, there is no way to know if more recent infections are less or more severe than earlier ones. I have seen rare mentions of "viral load", but they haven't been very informative.